Two-stage prestressed yielding anchor rod and yielding method

Abstract

The application discloses a prestressed two-stage yielding anchor rod and a yielding method, and relates to the technical field of tunnel engineering, which comprises an anchor rod, a fixing assembly comprising a tray and a fastening bolt, a yielding assembly comprising a sleeve piece, an expansion piece, a clamping piece and a limiting piece. The anchor rod is connected with the rock mass through the fixing assembly and the yielding assembly, the original supporting material is fully utilized, the original supporting system is improved, two-stage yielding is realized through the yielding assembly, and the required yielding amount can be quickly installed according to the actual deformation amount, so that the different deformation amount requirements on the site can be met. The prestress can be applied in time when the yielding anchor rod is installed, the deformation of the surrounding rock caused by the failure of timely support is prevented, and the construction safety is ensured.

Description

Technical Field

[0001] This invention relates to the field of tunnel engineering technology, and specifically to a prestressed two-stage pressure relief anchor bolt and a pressure relief method. Background Technology

[0002] Deep underground engineering construction is often accompanied by high ground stress and high confining pressure, especially in sedimentary rocks with significant stratification effects. Under water-rich conditions, large deformation phenomena can easily occur due to multiple factors such as rock swelling upon contact with water, delamination, displacement, and compression. These factors lead to large deformations, and the pressure on the surrounding rock varies at different stages of deformation. If effective measures are not taken to control the deformation in a timely manner, it will pose a great challenge to construction and operation. As the main support component currently used on site, anchor bolts, due to their high stiffness and small deformation, cannot adapt to such deformations. When the deformation exceeds the limit elongation, they will break, leading to support failure. Existing deformable anchor bolts also have some shortcomings; some have insufficient deformation capacity, while others have overly complex procedures. Excessive modifications to existing anchor bolts would increase the labor intensity of workers. According to the anchor bolt support characteristic curve and the surrounding rock convergence curve, increasing the deformation of the anchor bolt can significantly reduce the surrounding rock pressure at the intersection of the two curves, thus putting the anchor bolt in a relatively safe working state and maximizing the self-stabilizing capacity of the surrounding rock. Summary of the Invention

[0003] In view of the problems existing in the prior art, the present invention is proposed.

[0004] Therefore, the technical problem to be solved by this invention is that existing deformable anchor bolts have insufficient deformation and cannot meet the limit elongation.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a prestressed two-stage pressure relief anchor bolt, comprising, an anchor bolt;

[0006] A fixing assembly, connected to the anchor bolt, includes a tray and fastening bolts. The tray is disposed at one end of the anchor bolt and connected to the rock mass sidewall. The fastening bolts are disposed at the other end of the anchor bolt for connecting the anchor bolt to the rock mass; and...

[0007] A pressure-relieving assembly is disposed on one side of the fixed assembly and includes a sleeve, a telescopic component, a snap-fit ​​component, and a limiting component. The sleeve is disposed inside the tray and connected to the tray. The telescopic component is connected to the sleeve. The snap-fit ​​component is connected to the sleeve. The limiting component is disposed inside the sleeve.

[0008] The anchor rod passes through the fixing component and the pressure relief component and is connected to the rock mass.

[0009] As a preferred embodiment of the prestressed two-stage relief anchor bolt of the present invention, the sleeve component includes a first sleeve, a second sleeve, and a sleeve base connected to each other. The diameter of one end of the first sleeve tends to decrease, and the smaller diameter end of the first sleeve is inserted into the rock mass, while the other end is connected to the second sleeve. The sleeve base is connected to the other end of the second sleeve. The first sleeve, the second sleeve, and the sleeve base form a cavity through which the anchor bolt can pass.

[0010] As a preferred embodiment of the prestressed two-stage relief anchor bolt of the present invention, the snap-fit ​​component is disposed at one end where the second sleeve is connected to the first sleeve and at one end where the sleeve base is connected to the second sleeve, and is located in the first snap-fit ​​groove opened at one end of the first sleeve and the second snap-fit ​​groove opened at one end of the second sleeve. The sidewalls of the first snap-fit ​​groove and the second snap-fit ​​groove are provided with snap-fit ​​protrusions.

[0011] As a preferred embodiment of the prestressed two-stage relief anchor bolt of the present invention, the snap-fit ​​component includes a snap-fit ​​ring, a snap-fit ​​block, a locking block, and a secondary locking rod. The snap-fit ​​ring is connected to one end of the second sleeve. The snap-fit ​​block and the slot on the side wall of the snap-fit ​​ring are connected to a torsion spring via a rotating shaft. The locking block is disposed in the rotating groove of the inner cavity of the snap-fit ​​ring and is connected to the inner side wall of the snap-fit ​​ring via a telescopic spring. The secondary locking rod is disposed on the side walls of the first sleeve and the second sleeve and passes through the side wall of the snap-fit ​​ring to connect with the snap-fit ​​protrusion.

[0012] As a preferred embodiment of the prestressed two-stage relief anchor bolt of the present invention, the limiting member is disposed in the inner cavity of the sleeve base and includes a limiting ring, a pushing rod and an unlocking rod. One side of the limiting ring passes through the inner side wall of the sleeve base and is connected to the telescopic member. The pushing rod is disposed on the other side of the limiting ring and is connected to the inner side wall of the sleeve base cavity through a connecting rod. One end of the unlocking rod passes through the side wall of the sleeve base to the outside and the other end is connected to the pushing rod. The side wall of the unlocking rod is provided with an opening, and the inner diameter of the opening matches the pushing rod.

[0013] As a preferred embodiment of the prestressed two-stage relief anchor bolt of the present invention, the telescopic component includes an outer spring, an inner spring, and a piston. The outer spring is disposed on the outer wall of the sleeve component, with one end connected to the tray and the other end connected to the sleeve base. The inner spring is disposed on the inner wall of the sleeve component, with one end connected to one end of the inner side of the first sleeve and the other end connected to the piston. The piston is disposed in the inner cavity of the sleeve component and connected to the inner wall of the sleeve base. One end of the piston is connected to the limiting ring, and the other end is connected to the fastening bolt.

[0014] As a preferred embodiment of the prestressed two-stage relief anchor bolt of the present invention, wherein: the tray can slide along the outer wall of the sleeve, and the piston can slide along the inner wall of the sleeve.

[0015] Another object of the present invention is to provide a method for yielding pressure in a prestressed two-stage yielding anchor bolt, which includes the following steps:

[0016] Install pressure-relief anchor bolts;

[0017] First-stage pressure relief;

[0018] Secondary pressure relief.

[0019] As a preferred embodiment of the prestressed two-stage pressure relief method for anchor bolts described in this invention, in the first stage of pressure relief, the pallet and the outer wall of the sleeve slide relative to each other, the outer spring is compressed and deformed, providing deformation force to achieve the first stage of pressure relief.

[0020] As a preferred embodiment of the prestressed two-stage pressure relief method for anchor bolts described in this invention, in the second stage of pressure relief, the first stage of pressure relief ends, the tray abuts against the sleeve base, and the tension applied to the anchor bolt by the rock mass causes the piston to compress the inner spring and slide along the inner wall of the sleeve.

[0021] The beneficial effects of this invention are as follows: It proposes targeted control for severely stratified sedimentary rock layers, connecting anchor bolts to the rock mass through fixing and pressure-relief components. This fully utilizes existing support materials and improves the original support system. The pressure-relief components achieve two-stage pressure relief, and their installation can be quickly adjusted to meet varying deformation requirements on-site. Furthermore, prestress can be applied to the pressure-relief anchor bolts during installation to prevent excessive deformation due to insufficient support of the surrounding rock, eliminating concerns about breakage during use and ensuring construction safety. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the overall device of the present invention.

[0024] Figure 2 This is a partial exploded schematic diagram of the device of the present invention.

[0025] Figure 3 This is a bottom view of the overall device of the present invention.

[0026] Figure 4 This is a partial exploded schematic diagram of the device of the present invention.

[0027] Figure 5 This is an exploded view of the snap-fit ​​connector of the present invention.

[0028] Figure 6 This is a partial schematic diagram of the limiting member of the present invention.

[0029] Figure 7 This is a schematic diagram of the first-stage pressure relief of the present invention.

[0030] Figure 8 This is a schematic view of the two-stage pressure relief method of the present invention. Detailed Implementation

[0031] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0032] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0033] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places throughout this specification does not necessarily refer to the same embodiment, nor is it an embodiment that is mutually exclusive, either alone or selectively, with other embodiments.

[0034] Example 1

[0035] Reference Figure 1 - Figure 6 This is the first embodiment of the present invention. This embodiment provides a prestressed two-stage pressure relief anchor bolt, including an anchor bolt 100, a fixing component 200, and a pressure relief component 300. The anchor bolt 100 is connected to the surrounding rock mass through the fixing component 200 and the pressure relief component 300 to fix the anchor bolt. The pressure relief component 300 allows the anchor bolt 100 to have the deformation amount that should be generated by the surrounding rock mass, thereby protecting the anchor bolt 100 from failure due to excessive deformation and loss of support effect.

[0036] Specifically, the fixing component 200 is connected to the anchor rod 100 and includes a tray 201 and a fastening bolt 202. The tray 201 is located at one end of the anchor rod 100 and is connected to the side wall of the rock mass. The fastening bolt 202 is located at the other end of the anchor rod 100 and is used to connect the anchor rod 100 to the rock mass. After the anchor rod 100 is inserted into the surrounding rock mass, the tray 201 is close to the outer wall of the surrounding rock mass. The fastening bolt 202 is located at the tail end of the anchor rod 100 and is used to fasten the anchor rod 100 to the rock mass.

[0037] Furthermore, the pressure relief component 300 is disposed on one side of the fixed component 200, including a sleeve 301, a telescopic component 302, a snap-fit ​​component 303, and a limiting component 304. The sleeve 301 is disposed inside the pallet 201, that is, on the side away from the surrounding rock mass, and is used to generate pressure relief deformation along the sleeve 301 after the pallet 201 is deformed by the surrounding rock mass. One end of the sleeve 301 is connected to the pallet 201 from the side wall. The telescopic component 302 is connected to the sleeve 301. When the pallet 201 undergoes pressure relief displacement on the sleeve 301, the telescopic component 302 provides it with telescopic support force. The snap-fit ​​component 303 is connected to the sleeve 301 and is used to adjust the assembly of the sleeve 301 according to the required deformation amount after calculation, so that the overall device after two-stage pressure relief is exactly in the final support state. The limiting component 304 is disposed inside the sleeve 301 and is used to prevent the second-stage pressure relief deformation from entering the working state before the first-stage pressure relief ends, thus providing a support effect for the entire anchor bolt 100.

[0038] It should be noted that the anchor bolt 100 passes through the anchor bolt hole opened in the middle of the fixing component 200 and the pressure relief component 300 and is connected to the rock mass.

[0039] In summary, because of the snap-fit ​​component 303, the sleeve component 301 can be installed with the actual deformable length according to the deformation required by the surrounding rock of the specific construction site. This ensures that the rock mass support effect of the anchor rod 100 after two-stage pressure relief still meets the requirements of bearing capacity and other requirements. The setting of the overall pressure relief component 300 also provides the anchor rod 100 with the required pressure relief deformation, so that the anchor rod 100 will not fail and lose its support effect, thus affecting construction safety. Moreover, the setting of the pressure relief component 300 and other components does not change the existing specific structure of the anchor rod 100, is simple to operate, and is suitable for actual construction site work.

[0040] Example 2

[0041] Reference Figure 2 - Figure 6 This is the second embodiment of the present invention, which is based on the previous embodiment.

[0042] Specifically, the sleeve component 301 includes a first sleeve 301a, a second sleeve 301b, and a sleeve base 301c. The first sleeve 301a, the second sleeve 301b, and the sleeve base 301c are connected to each other. The tip diameter of the first sleeve 301a tends to decrease, and the smaller diameter end of the first sleeve 301a is inserted into the rock mass, while the other end is connected to the second sleeve 301b. The sleeve base 301c is connected to the other end of the second sleeve 301b. The first sleeve 301a, the second sleeve 301b, and the sleeve base 301c form a cavity through which the anchor rod 100 can pass.

[0043] Preferably, during the specific on-site installation, the quantity, length, and other parameters of the second sleeve 301b can be calculated based on the actual required deformation. That is, the assembly of a sleeve 301 can be formed by splicing together a first sleeve 301a, a sleeve base 301c, and several second sleeves 301b to meet the deformation requirements of the surrounding rock mass at the construction site where the anchor bolt 100 is located.

[0044] Furthermore, a snap-fit ​​element 303 for completing the splicing of the sleeve components 301 is provided at the end where the second sleeve 301b connects to the first sleeve 301a, and at the end where the sleeve base 301c connects to the second sleeve 301b. That is, each second sleeve 301b to be assembled has a snap-fit ​​element 303 at the end where it connects to the first sleeve 301a, and the sleeve base 301c is used to connect with the tail end of the last assembled second sleeve 301b. The connection position is also provided with a snap-fit ​​component 303. After the splicing is completed, the snap-fit ​​component 303 is located in the first snap-fit ​​groove 301a-1 opened at the tail end of the first sleeve 301a and the second snap-fit ​​groove 301b-1 opened at the tail end of the second sleeve 301b. It does not affect the outer wall of the overall sleeve component 301. The side walls of the first snap-fit ​​groove 301a-1 and the second snap-fit ​​groove 301b-1 are provided with the same snap-fit ​​protrusion 301d, which is used to achieve the splicing effect with the snap-fit ​​component 303.

[0045] Specifically, the locking component 303 includes a locking ring 303a, a locking block 303b, a locking block 303c, and a secondary locking rod 303d. The locking ring 303a is connected to one end of the second sleeve 301b. The locking ring 303a is not a complete continuous ring; it has a notch that matches the locking protrusion 301d, which is also used to align the splicing holes during assembly. Each locking block 303b is set in this notch, and its slot is connected to a torsion spring via a rotating shaft. This allows the locking block 303b to engage with the locking protrusion 301d when it contacts the locking protrusion 303c. b can rotate around the torsion spring and enter the slot, so that the snap-fit ​​protrusion 301d can smoothly provide the snap-fit ​​block 303b. Under the action of the torsion spring, the snap-fit ​​block 303b will return to the initial closed position. However, since the torsion spring and the rotating shaft make the snap-fit ​​block 303b only rotate in one direction, it is impossible for the snap-fit ​​protrusion 301d to slide out at this time. At this time, the connection between the second sleeve 301b and the tail of the first sleeve 301a is realized, or the mutual snap-fit ​​between several second sleeves 301b is realized. Similarly, the connection between the sleeve base 301c and the last section of the second sleeve 301b is based on the same principle.

[0046] Furthermore, after the splicing is completed, the entire sleeve component 301 needs to be locked to prevent deformation forces from damaging the sleeve, that is, the locking block 303c enters the working state.

[0047] Specifically, the locking block 303c is set in the rotating groove 303a-1 inside the cavity of the snap ring 303a. The opening position of the rotating groove 303a-1 is set at the position after the snap protrusion 301d has completed the pressing work with the snap block 303b. That is, after the snap protrusion 301d has completed the splicing work, a certain section of the sleeve being spliced ​​is rotated so that the snap protrusion 301d enters the rotating groove 303a-1 from the opening. Since the top of the rotating groove 303a-1 is closed, the snap protrusion 301d is further prevented from being broken by the deformation force of the rock mass. At the same time, after being completely rotated to the final position of the rotating groove 303a-1, the position of the snap protrusion needs to be limited. At this time, the locking block 303c needs to be put into operation.

[0048] Furthermore, the locking block 303c is located on the bottom side wall of the final position of the rotating groove 303a-1, and is connected to the inner side wall of the snap ring 303a by the telescopic spring 303c-1. In a preferred embodiment, the side of the locking block 303c that first contacts the snap protrusion 301d is provided with an inclined surface, which makes it easy for the snap protrusion 301d to squeeze it first into the top of the rotating groove 303a-1, and then pop it out by the action of the telescopic spring 303c-1, snapping it into the opening at the bottom of the snap protrusion 301d, thereby locking the position of the snap protrusion 301d.

[0049] Furthermore, during the pressure relief operation, the tray 201 will displace outward along the sleeve 301. To prevent the sleeve from breaking or becoming unstable at this time, thus affecting the pressure relief operation, a secondary locking rod 303d is used for protection. Specifically, it is installed in the opening on the outer wall of the tail end of the first sleeve 301a and the second sleeve 301b. In its initial state, it extends out of the outer wall, slightly higher than the outer wall of the sleeve, and can extend and retract within the opening. It should be noted that when the secondary locking rod 303... After d is fully inserted into the opening, it does not affect the sliding of the tray 201 on the outer wall of the sleeve. Furthermore, the secondary locking rod 303d, after extending into the opening, passes through the side wall of the snap ring 303a and connects with the snap protrusion 301d. The side wall of the snap protrusion 301d has a slot that matches the secondary locking rod 303d. Moreover, the side wall of the snap ring 303a also has an opening that allows the inner end of the secondary locking rod 303d to extend in. The position of this opening is the position after the snap protrusion 301d completes the above-mentioned rotational locking operation.

[0050] It should be noted that the position of the secondary locking rod 303d in the initial state does not affect the splicing work between the second sleeve 301b, the sleeve base 301c and the first sleeve 301a. It only affects the spliced ​​sleeve after the tray 201 starts to give pressure and the secondary locking rod 303d extends in. This is also to ensure the integrity of the entire sleeve when giving pressure.

[0051] Furthermore, a limiting member 304 is disposed within the inner cavity of the sleeve base 301c to prevent the secondary pressure release from proceeding before the primary pressure release is completed. This member includes a limiting ring 304a, a push rod 304b, and an unlocking rod 304c. One side of the limiting ring 304a passes through the inner wall of the sleeve base 301c and connects to the telescopic member 302. The push rod 304b is disposed on the other side of the limiting ring 304a and is connected to the inner wall of the sleeve base 301c via a connecting rod 304a-1. When the push rod 304b is pushed, it compresses the connecting rod 304a-1. It should be noted that... Yes, the connecting rod 304a-1 is divided into two sections. The first section is connected to the push rod 304b, and it will retract into the second section after being pushed. One end of the unlocking rod 304c passes through the side wall of the sleeve base 301c to the outside, and the other end is connected to the push rod 304b. The side wall of the unlocking rod 304c has an opening 304c-1. The inner diameter of the opening 304c-1 matches the push rod 304b. In the initial state, the position of the opening 304c-1 is higher than that of the push rod 304b, so it cannot retract through the opening 304c-1, thereby preventing the piston 302c from starting to move.

[0052] Furthermore, the telescopic component 302 includes an outer spring 302a, an inner spring 302b, and a piston 302c. The outer spring 302a is disposed on the outer side wall of the sleeve component 301, with one end connected to the tray 201 and the other end connected to the sleeve base 301c. The inner spring 302b is disposed on the inner side wall of the sleeve component 301, with one end connected to one end of the inner side of the first sleeve 301a and the other end connected to the piston 302c. The piston 302c is disposed in the inner cavity of the sleeve component 301 and connected to the inner side wall of the sleeve base 301c. One end of the piston 302c is connected to the limiting ring 304a, and the other end is connected to the fastening bolt 202.

[0053] When the first-stage pressure relief is not completed, the limiting ring 304a extends out of the inner wall of the sleeve base 303c to restrict the piston 302c from sliding on the inner wall of the sleeve, thus preventing the second-stage pressure relief from starting. When the first-stage pressure relief is completed, and the tray 201 is in contact with the side wall of the sleeve base 303c, it presses the unlocking rod 304c downward, so that the opening 304c-1 corresponds to the push rod 304b. At this time, the piston 302c starts to move and compresses the inner spring 302b, pushing the limiting ring 304a into the inner cavity of the sleeve base 303c, and the second-stage pressure relief begins to work.

[0054] In summary, the pallet 201 can slide along the outer wall of the sleeve 301, and the piston 302c can slide along the inner wall of the sleeve 301, thereby achieving two-stage pressure relief to protect the anchor bolt 100 from failure. The deformation that the sleeve 301 can provide can be calculated and spliced ​​for installation, making it suitable for various construction sites.

[0055] Example 3

[0056] Reference Figure 1 - Figure 8 This is the third embodiment of the present invention, which provides a method for yielding pressure on a prestressed two-stage yielding anchor bolt.

[0057] To install the pressure relief anchor bolt, first drill a hole in the support tunnel, matching the diameter of the hole with the diameter of the bolt. After reaching the bottom, remove the drill rod and replace it with a larger drill bit to thicken the borehole opening. The diameter of the thickened section should match the outer diameter of the pressure relief sleeve. Then, level the surrounding rock surface at the borehole opening to ensure that the tray 201 is as perpendicular as possible to the borehole after installation. Alternatively, wooden wedges can be used to achieve leveling.

[0058] Next, inject anchoring agent into the borehole. Then, with the end of the rod facing the bottom of the hole, pass it through the piston 302c, sleeve 301, and tray 201 in sequence and install it in the borehole. Tighten the fastening bolt 202 in time to fix each component, so that the piston 302c and tray 201 are in close contact with the sleeve 301. Before the anchoring agent solidifies, tighten the fastening bolt 202 with a drilling machine to achieve the designed preload of 80KN. The piston 302c, fastening bolt 202, and tray 201 can be made of hard alloy or high-quality steel to ensure sufficient strength.

[0059] As the surrounding rock continues to deform, when the surrounding rock pressure reaches the set first-level relief pressure, the tray 201 begins to compress the outer spring 302a and slides along the outer wall of the sleeve.

[0060] After the first-stage pressure relief ends, under the continued deformation of the surrounding rock, when the surrounding rock pressure reaches the set second-stage pressure relief, the piston 302c begins to compress the inner spring, which slides along the inner wall of the sleeve.

[0061] Preferably, when the sleeve length is 20cm, the preset limit of the initial and secondary pressure relief is 15cm, and the total pressure relief is 15×2=30cm. When the length is 30cm, the preset limit of the pressure relief is 25cm, and the total pressure relief is 25×2=50cm, not including the extension length of the rod.

[0062] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A prestressed two-stage relief anchor bolt, characterized in that: include, Anchor bolt (100); A fixing assembly (200), connected to the anchor bolt (100), includes a tray (201) and fastening bolts (202). The tray (201) is disposed at one end of the anchor bolt (100) and connected to the rock mass sidewall. The fastening bolts (202) are disposed at the other end of the anchor bolt (100) for connecting the anchor bolt (100) to the rock mass. A pressure relief assembly (300) is disposed on one side of the fixed assembly (200) and includes a sleeve (301), a telescopic member (302), a snap-fit ​​member (303), and a limiting member (304). The sleeve (301) is disposed inside the tray (201) and connected to the tray (201). The telescopic member (302) is connected to the sleeve (301). The snap-fit ​​member (303) is connected to the sleeve (301). The limiting member (304) is disposed inside the sleeve (301). The anchor bolt (100) passes through the fixing component (200) and the pressure relief component (300) and is connected to the rock mass; The sleeve component (301) includes a first sleeve (301a), a second sleeve (301b), and a sleeve base (301c). The first sleeve (301a), the second sleeve (301b), and the sleeve base (301c) are connected to each other. The diameter of one end of the first sleeve (301a) is decreasing. The smaller diameter end of the first sleeve (301a) is inserted into the rock mass, and the other end is connected to the second sleeve (301b). The sleeve base (301c) is connected to the other end of the second sleeve (301b). The first sleeve (301a), the second sleeve (301b), and the sleeve base (301c) form a cavity through which the anchor rod (100) can pass. The snap-fit ​​component (303) is disposed at the end where the second sleeve (301b) is connected to the first sleeve (301a) and at the end where the sleeve base (301c) is connected to the second sleeve (301b), and is located in the first snap-fit ​​groove (301a-1) opened at one end of the first sleeve (301a) and the second snap-fit ​​groove (301b-1) opened at one end of the second sleeve (301b). The side walls of the first snap-fit ​​groove (301a-1) and the second snap-fit ​​groove (301b-1) are provided with snap-fit ​​protrusions (301d). The locking component (303) includes a locking ring (303a), a locking block (303b), a locking block (303c), and a secondary locking rod (303d). The locking ring (303a) is connected to one end of the second sleeve (301b). The locking block (303b) is connected to a torsion spring via a rotating shaft through a slot in the side wall of the locking ring (303a). The locking block (303c) is disposed on the locking ring (303a). The locking block (303c) is located in the rotating groove (303a-1) of the inner cavity, and the locking block (303c) is connected to the inner side wall of the snap ring (303a) through the telescopic spring (303c-1). The secondary locking rod (303d) is provided on the side wall of the first sleeve (301a) and the second sleeve (301b), and the secondary locking rod (303d) passes through the side wall of the snap ring (303a) and is connected to the snap protrusion (301d). The telescopic component (302) includes an outer spring (302a), an inner spring (302b), and a piston (302c). The outer spring (302a) is disposed on the outer side wall of the sleeve component (301), with one end connected to the tray (201) and the other end connected to the sleeve base (301c). The inner spring (302b) is disposed on the inner side wall of the sleeve component (301), with one end connected to the inner side of the first sleeve (301a) and the other end connected to the piston (302c). The piston (302c) is disposed in the inner cavity of the sleeve component (301), connected to the inner side wall of the sleeve base (301c), with one end connected to the limiting ring (304a) and the other end connected to the fastening bolt (202).

2. The prestressed two-stage relief anchor bolt as described in claim 1, characterized in that: The limiting member (304) is disposed in the inner cavity of the sleeve base (301c) and includes a limiting ring (304a), a push rod (304b) and an unlocking rod (304c). One side of the limiting ring (304a) passes through the inner side wall of the sleeve base (301c) and is connected to the telescopic member (302). The push rod (304b) is disposed on the other side of the limiting ring (304a) and is connected to the inner side wall of the sleeve base (301c) through a connecting rod (304a-1). One end of the unlocking rod (304c) passes through the side wall of the sleeve base (301c) to the outside, and the other end is connected to the push rod (304b). The side wall of the unlocking rod (304c) is provided with an opening (304c-1), and the inner diameter of the opening (304c-1) matches the push rod (304b).

3. The prestressed two-stage relief anchor bolt as described in claim 1, characterized in that: The tray (201) can slide along the outer wall of the sleeve (301), and the piston (302c) can slide along the inner wall of the sleeve (301).

4. A method for yielding pressure in a prestressed two-stage yielding anchor bolt, characterized in that: Including a prestressed two-stage relief anchor bolt as described in any one of claims 1-3; and, Install pressure-relief anchor bolts; First-stage pressure relief; Secondary pressure relief.

5. The method for yielding pressure in a prestressed two-stage yielding anchor bolt as described in claim 4, characterized in that: During the first stage of pressure relief, the tray (201) slides relative to the outer wall of the sleeve (301), and the outer spring (302a) is compressed and deformed to provide deformation force, thereby achieving the first stage of pressure relief.

6. The method for yielding pressure in a prestressed two-stage yielding anchor bolt as described in claim 5, characterized in that: During the second-stage pressure relief, the first-stage pressure relief ends, the tray abuts against the sleeve base (301c), and the rock mass applies tension to the anchor rod (100), causing the piston (302c) to compress the inner spring (302b) and slide along the inner wall of the sleeve (301).

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